Apparatus and methods for tracking administering of medication by medication injection devices

ABSTRACT

A method of tracking injections includes depressing a plunger of a medication injection device, and sending and receiving ultrasonic signals from a plunger head installed within a barrel of the medical injection device. The method also includes measuring a time of flight for the signals to travel through the medication, and determining a position of the plunger head based on the time of flight of the signals. Additionally, a plurality of data samples representative of the position of the plunger are logged, and a distance the plunger head travels is calculated. This is used to calculate the quantity of the medication dispensed based on the distance the plunger head travels. An external device is then used to back-interpolate a time corresponding to each data sample logged in order to determine the time the quantity of medication was dispensed.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/329,605, filed Apr. 29, 2016, which is incorporated by reference inits entirety.

BACKGROUND Technical Field

The present disclosure relates generally to the field of tracking theadministration of medication, and more particularly, apparatus andmethods for tracking the administration of medication by medicationinjection devices.

Background Description

Measuring the quantity and recording the timing of a drug'sadministration is an integral part of many disease treatments. For manytreatments, to achieve the best therapeutic effect, specific quantitiesof a drug may need to be injected specific times of day. For example,individuals suffering from diabetes may be required to inject themselvesregularly throughout the day in response to measurements of their bloodglucose. The frequency and volume of insulin injections must becarefully tracked and controlled to keep the patient's blood glucoselevel within a healthy range. Currently, there are a limited number ofmethods or devices for automatically tracking the drug administrationwithout requiring the user to manually measure and record the volume,date, and time. A variety of glucose injection syringes/pens have beendeveloped, but there is much room for significant advancement in thetechnology in order to reduce the size, lower the cost, and enhanced thefunctionality thus making them a more viable long term solution. Forexample, current insulin pens are often disposable, but do not includedosage tracking. A smaller portion of the market is composed of reusablepens which are more expensive, and still don't include good dosagetracking capabilities.

SUMMARY

The present disclosure is directed to apparatuses and methods of drugadministration using a medication injection device.

In one aspect, the present disclosure is directed to a plunger head fora medication injection device. The plunger head may include a firstcomponent that houses electronic components and a second component thatcouples to the first component to form the plunger head. When theplunger head is installed within a barrel of the medication injectiondevice the second component may separate the first component frommedication contained within the barrel.

In another aspect, the present disclosure is directed to a method ofmanufacturing a plunger head for a medication injection device. Themethod may include assembling a first component of the plunger head,which houses electronic components, using lower temperature assemblysteps. The method may also include sterilizing the first component usinga lower temperature sterilization method. The method may further includemolding a second component of the plunger head from an elastomer todefine a bucket shape. The method may also include sterilizing the firstcomponent using a higher temperature sterilization method. The methodmay further include attaching the first component to the secondcomponent to form the plunger head.

In another aspect, the present disclosure is directed to another plungerhead for a medication injection device. The plunger head may include atransducer that sends and receives ultrasonic signals, an antenna, and amicrocontroller that interfaces with the transducer and the antenna. Theplunger head may also include a power source that powers themicrocontroller and the transducer. The microcontroller may beprogrammed with instructions to calculate data representative of thequantity of medication dispensed from the barrel and transmit the datato a remote device via the antenna and to automatically differentiate anair shot of medication versus an injection of medication.

In another aspect, the present disclosure is directed to a method oftracking injections of a medication delivered by a medication injectiondevice. The method may include depressing a plunger of the medicationinjection device. The method may also include sending and receivingultrasonic signals from a plunger head installed within a barrel of themedical injection device. The method may further include measuring thetime it takes for the signals to travel through the medication to an endof the barrel and return to the plunger head. The method may alsoinclude calculating the distance the plunger head travels based on achange in the time. The method may further include calculating aquantity of the medication dispensed based on the distance the plungerhead travels. The method may also include automatically differentiatingan air shot of medication versus an injection of medication using analgorithm, wherein the algorithm is programmed to recognize an air shotbased on one or more conditional states. The method may also includeselectively transmitting wirelessly the quantity of the medicationdispensed to a remote device.

In another aspect, the present disclosure is directed to another plungerhead for a medication injection device. The plunger head may include atransducer that sends and receives ultrasonic signals, an antenna, and amicrocontroller that interfaces with the transducer and the antenna. Theplunger head may also include a power source that powers themicrocontroller and the transducer. The microcontroller may beprogrammed with instructions to calculate a quantity of medicationdispensed from a barrel of the medication injection device based on aplurality of logged data samples and transmit the quantity of medicationdispensed to a remote device via the antenna. The microcontroller mayalso be programmed with instructions to log each data sample in order togenerate the plurality of logged data samples at an approximatelyregular interval. After the quantity of medication is transferred to theremote device, the time and date maintained by the remote device may beused to back-interpolate the time corresponding to each data sample inorder to determine the approximate time the quantity of medication wasdispensed.

In another aspect, the present disclosure is direction to another methodof tracking injections of a medication delivered by a medicationinjection device. The method may include depressing a plunger of themedication injection device and sending and receiving ultrasonic signalsfrom a plunger head installed within a barrel of the medical injectiondevice. The method may also include measuring the time it takes for thesignals to travel through the medication to an end of the barrel andreturn to the plunger head and determining a position of the plungerhead based on the travel time of the signals and logging a data samplerepresentative of the position. The method may further include logging aplurality of the data samples representative of the position of theplunger at an approximately regular interval. The method may alsoinclude calculating the distance the plunger head travels based on achange in the position and calculating a quantity of the medicationdispensed based on the distance the plunger head travels. The method mayfurther include selectively transmitting wirelessly the quantity of themedication dispensed to a remote device. The method may also includeback-interpolating the time corresponding to each data sample logged inorder to determine the approximate time the quantity of medication wasdispensed, using the time and date maintained by the remote device as areference time.

In another aspect, the present disclosure is directed to another plungerhead for a medication injection device. The plunger head may include atransducer that sends and receives ultrasonic signals, an antenna, and amicrocontroller that interfaces with the transducer and the antenna. Theplunger head may also include a power source that powers themicrocontroller and the transducer and a temperature sensor thatmeasures a temperature associated with the plunger head. The plungerhead may be stored in a low-power sleep mode prior to use during whichthe plunger head periodically wakes up to measure the temperature.

In another aspect, the present disclosure is directed to a method ofoperation for a medication injection device that has a temperaturesensor associated with the device that measures an ambient temperature.The method may include entering the medication injection device into alow-power sleep mode. The method may also include periodically measuringthe ambient temperature while in the low-power sleep mode and detectinga temperature change and then transitioning the medication injectiondevice into an initialization mode. The method may further includepairing the medication injection device with a remote device while inthe initialization mode. The method may also include entering anoperational mode after a successful pairing of the medication devicewith the remote device. The method may further include measuring andlogging a plunger head position of the medication injection device oncein the operational mode.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a medication injection device, whichincludes a plunger head according to an exemplary embodiment.

FIG. 2 is a schematic of the plunger head of FIG. 1.

FIG. 3 is a cross-sectional schematic illustrating another embodiment ofthe plunger head of FIG. 1

FIG. 4 is a flow chart illustrating a method of manufacturing theplunger head of FIG. 3.

FIG. 5 is a schematic illustrating the behavior of ultrasonic signalstransmitted by the plunger head of FIG. 2 or 3.

FIG. 6 is a perspective view of a medication injection device, whichincludes a plunger head and a cuff according to an exemplary embodiment.

FIG. 7 is a flow chart illustrating a method of tracking administeringof medication by a medication injection device, according to anexemplary embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings. Where possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

FIG. 1 shows a perspective view of a medication injection device in theform of a syringe 10 designed for ejecting a fluid. Syringe 10 mayinclude a barrel 12, a plunger 14, a needle 16, and a hub 18 connectingneedle 16 to barrel 12. Barrel 12 may be configured to contain a fluid,for example, a medication 20 and syringe 10 may be configured todispense medication 20 from needle 16 when plunger 14 is depressed. Astandard syringe usually contains a plunger head at the end of theplunger that seals the top of the barrel and forces the fluid out theneedle when the plunger is depressed. The plunger head for a standardsyringe is usually just a piece of molded rubber.

For syringe 10 shown in FIG. 1, the standard plunger head has beenreplaced with a smart or intelligent plunger head 22 that is configuredto measure and register the quantity of medication 20 administered andthe time and date of administration. Plunger head 22 may be installed ina standard syringe by withdrawing plunger 14 and removing the standardplunger head and installing smart plunger head 22. In some embodiments,syringe 10 may be manufactured and supplied with a smart plunger head 22preinstalled. Smart plunger head 22 may be referred herein as eithersmart plunger head 22 or plunger head 22.

Plunger head 22 may be sized to correspond with the size of barrel 12.For example, plunger head 22 may be formed to fit any size syringe. Forexample, plunger head 22 may be sized to fit a 1 ml, 2 ml, 3 ml, 5 ml,10 ml, 20 ml, 30 ml, or 50 ml syringe.

FIG. 2 shows a schematic of plunger head 22, according to an exemplaryembodiment. Plunger head 22 may include a transducer 24, amicrocontroller 26, a power source 28, and an antenna (e.g., for nearfield communication (NFC) or a transceiver 30 (e.g., for BLUETOOTH lowenergy (BLE) communication). In some embodiments, plunger head 22 mayalso include a temperature sensor 36. Temperature sensor 36 may beconfigured to measure the ambient temperature, which may be generallyrepresentative of a temperature of plunger head 22 and/or medication 20.

Transducer 24 may be configured to send and receive ultrasonic signals.Microcontroller 26 may be programmed with instructions to control theoverall operation of the plunger head. Transceiver 30 may be configuredto wirelessly communicate with a remote device (e.g., a smart phone, aglucose monitor, an insulin pump, or a computer) using one or morewireless communication methods. The one or more wireless communicationmethods may include, for example, radio data transmission, Bluetooth,BLE, near field communication (NFC), infrared data transmission,electromagnetic induction transmission, and/or other suitableelectromagnetic, acoustic, or optical transmission methods. Power source28 may be configured to power transducer 24, microcontroller 26,transceiver 30, temperature sensor 36, and other electronic componentsof plunger head 22.

In some embodiments, as shown in FIG. 2, the components of plunger head22 may be at least partially encapsulated in an elastomer 21 (e.g.,rubber, ethylene propylene (EPM), Nitrile (NBR), ethylene propylenediene (EPDM), polybutadiene, or polisoprene) that is shaped to defineplunger head 22.

In some embodiments, plunger head 22 may formed of a plurality ofcomponents. For example, plunger head 22 may be formed of a firstcomponent 31 and a second component 33 that may be fixedly or releasablycoupled together such that first component 31 and second component 33may form plunger head 22, as shown in FIG. 3. First component 31 andsecond component 33 may each take a variety of shapes. FIG. 3 shows across-section of one illustrative example where first component 31 maybe shaped to define a plug shape while second component 33 may be shapedto define a bucket shape configured to receive the plug shaped firstcomponent 31. When installed in barrel 12, plunger head 22 may beoriented such that second component 33 sits below first component 31such that second component 33 may separate first component 31 frommedication 20 contained within barrel 12. As a result, contact withmedication 20 within barrel 12 may be limited to second component 33(i.e., first component 31 may be prevented from contacting medication20). Such an arrangement may be advantageous because first component 31and second component 33 may be manufactured from different materials ifdesired and the available options of materials for first component 31may be greater because compatibility with medication 20 may beeliminated as a consideration. Second component 33 may be manufacturedfrom elastomers or other materials commonly used to manufacture plungerheads thus reducing or eliminating compatibility concerns, which mayreduce and simplify regulatory hurdles and testing. First component 31may be manufactured from the same material as second component 33 orfrom different materials including those which may not be compatiblewith medication 20. For example, second component may be formed of anelastomer (e.g., butyl rubber) while first component may be formed ofanother plastic, elastomer, or rubber (e.g., silicone rubber).

In some embodiments, as shown in FIG. 3, the electronic components(e.g., transducer 24, microcontroller 26, power source 28, transceiver30, and temperature sensor 36) may be housed in first component 31 whilesecond component 33 may be a simple elastomer mold or liner designed toseparate first component 31 from medication 20. In other words, theelectronic components may be isolated from medication 20 within firstcomponent 31. In some embodiments, transducer 24, transceiver 30,microcontroller 26, and power source 28 may be plate cylindricallyshaped and arranged in a pancake stack configuration within firstcomponent 31.

The thickness of second component 33 may vary. For example, in someembodiments, the thickness of second component may be about 0.5millimeters, about 0.6 millimeters, about 0.7 millimeters, about 0.8millimeters, about 0.9 millimeters, about 1 millimeter, about 1.1millimeter, greater than about 1.1 millimeter, or less than about 0.5millimeters.

In some embodiments, as shown in FIG. 3, first component 31 may include,among other things, a structural support system 35. Structural supportsystem 35 may be designed to prevent unintended deformation of firstcomponent 31 so that mechanical tolerances may be maintained withdesired ranges. In addition, structural support system 35 may bedesigned to protect (e.g., prevent damage) of the electronic componentsdue to compressive forces applied to plunger head 22 by plunger 14 whenmedication 20 is being injected. An upper surface of structural supportsystem 35 may be designed to function as a “push plate” for plunger 14and may be designed to uniformly distribute the compressive forcesapplied by plunger 14.

Structural support system 35 may be, for example, a rigid skeleton,cylinder, container, or frame work that surrounds or encloses one ormore of the electronic components. Although FIG. 3 shows structuralsupport system 35 surrounding all the electronic components, it iscontemplated that in some embodiments, less than all or a portion of theelectronic components may be contained within or surrounded by aboundary of structural support system 35. In some embodiments, firstcomponent 31 may be encapsulated, over-molded, or sealed within acoating (e.g., elastomer, silicone, plastic, or rubber coating).

In some embodiments, one or more of the electronic components may beexposed from first component 31. For example, in some embodiments, aportion of transducer 24 may be exposed from the bottom of firstcomponent 31 so that when first component 31 is inserted within secondcomponent 33, it mates flush with second component 33.

In some embodiments, first component 31 may also be designed tofacilitate proper positioning and orientation of one or more of theelectronic components. For example, the shape of first component 31 andsecond component 33 may be such that when first component 31 is insertedinto second component 33, transducer 24 may be pointed generally down acenter of barrel 12 when installed. In some embodiments, secondcomponent 33 may also be designed to facilitate proper orientation ofantenna/transceiver 30 when receiving first component 31.

Structural support system 35 may be made generally semi rigid or rigidand may be formed of a variety of different materials, for example,plastic, elastomers, composites, metals, or combinations thereof.

In some embodiments, first component 31 may also be arranged to provideadditional functionality including, for example, power source 28 (e.g.,battery). For example, power source 28 may be positioned such that whenno compressive forces are applied to first component 31, then there isno electrical contact between power source 28 and the electroniccomponents, thereby keeping the other electronic components powered down(i.e., conserving power). But when compressive forces are applied tofirst component 31, power source 28 or one or more of the otherelectronic components may be moved and brought into electrical contactthereby powering up. In other words, in some embodiments, power source28 may be positioned within first component 31, such that thecompressive force applied by plunger 14 acts as an off/off switch, whichinitiates (e.g., wakes up or powers up) the electronic components ofplunger head 22.

Separating plunger head 22 into first component 31 (that house theelectronic components and second component 33 (that contacts themedication) may provide additional advantages. For example, a challengewith monolithic encapsulating or overmolding of electronic components isthat the process usually exposes the electronic components to highertemperatures during both the molding step and later sterilizationstep(s), which may damage the electronic components, in particular,power source 28 (e.g., the battery). By splitting plunger head 22 intoseparate components (i.e., first component 31 and second component 33),a lower temperature (e.g., about 60 degrees Celsius or less) series ofsteps for manufacturing and sterilization can be employed for firstcomponent 31, which houses the electronic components, while a highertemperature (e.g., greater than about 60 degrees Celsius) series ofsteps for manufacturing and sterilization can be employed for secondcomponent 33, which contacts medication 20. The first component 31 andsecond component 33 may thenbe attached (e.g., by adhesive, bonding, orfriction), or another attachment means to form a completed sealed andsterile plunger head 22.

Although the multiple component arrangements (e.g., first component 31and second component 33) is described herein with reference to plungerhead 22, it is contemplated that this multiple or separate componentarrangement may be utilized in other applications where electroniccomponents are being packaged (e.g., encapsulated or over-molded) forapplications of use where they are alongside sensitive materials (e.g.,liquids, medications, chemicals, etc.).

A method 200 of manufacturing plunger head 22 formed of first component31 and second component 33 will now be explained with reference to FIG.4. Method 200 may include, at step 202, assembling first component 31 ofplunger head 22, which houses the electronic components, using a lowertemperature assembly method. Method 200 may also include, at step 204,sterilizing first component 31 using a lower temperature sterilizationmethod. Method 200 may also include, at step 206, molding secondcomponent 33 of plunger head 22 from an elastomer to define, forexample, a bucket shape). Method 200 may also include, at step 208,sterilizing a second component 33 using a higher temperaturesterilization method. Method 200 may also include, at step 210,attaching first component 31 to second component 33 to form plunger head22. First component 31 and second component 33 may then be attached(e.g., by adhesive, bonding, or friction), or another attachment meansto form a completed seal and sterile plunger head 22.

Transducer 24 may be an actuator, piezoelectric element, or speaker-likevoice coil configured to generate and send a pressure wave or ultrasonicsignal. Transducer 24 may be sized to be slightly smaller than the innerdiameter of barrel 12. As shown in FIG. 5, transducer 24 may beconfigured to generate ultrasonic signals 25 (e.g., radiated soundenergy waves) and send the ultrasonic signals 25 down barrel 12 towardhub 18 and needle 16. The ultrasonic signals can travel throughmedication 20 along the length of barrel 12 and bounce or reflect off anend 27 of barrel 12 and travel back through medication 20 to plungerhead 22. The reflected ultrasonic signals can be received and detectedby transducer 24. The speed of sound in medication 20 may be a knownvalue and thus a distance D can be calculated very accurately based onthe time it takes for a ultrasonic signal to travel down and back fromtransducer 24. As plunger head 22 is moved down barrel 12 distance Dwill change and by knowing the diameter of barrel 12 then the volume ofmedication 20 dispensed may be calculated based on the change indistance D.

As shown in FIG. 5, in some embodiments, a porous membrane 29 may beplaced within barrel 12 at end 27. Porous membrane 29 may be designed toallow medication 20 to pass through while providing a surface with goodreflective properties for the ultrasonic signals 25 to reflect from.Utilizing porous membrane 29 may improve the accuracy of the reflectivewave detection and thereby the distance and volume calculations. It iscontemplated that other materials may be used besides a porous membrane.It is also contemplated that the geometry of barrel 12 at end 27 maydictate whether a porous membrane is needed. For example, in someembodiments the geometry of end 27 may be designed to produce thedesired reflective properties avoiding the need to porous membrane 29.

In some embodiments, microcontroller 26 may be configured to use thetemperature of medication 20 to compensate for variations in thetemperature that would affect the speed of sound within the medication,thus improving the accuracy of the distance and volume calculations.

In some embodiments, microcontroller 26 (or simply a controller) may beattached to a printed circuit board and may include one or moreprocessors, including for example, a central processing unit (CPU). Theprocessors may include any suitable type of commercially availableprocessor or may be a custom design. Microcontroller 26 may includeadditional components, for example, non-volatile memory (e.g., a flashmemory), volatile memory (e.g., a random access memory (RAM)), and otherlike components, configured to store information). In some embodiments,microcontroller or controller may include logic that can be dynamicallyupdated in software or the like or may have static logic that isimplemented in hardware.

Microcontroller 26 may be programmed with instructions to control theoperation of transducer 24. Microcontroller 26 may be programmed withinstructions to calculate data representative of the quantity ofmedication 20 dispensed. For example, in some embodiments,microcontroller 26 may be programmed to detect and record the reflectiontimes of the ultrasonic signals 25. Based on the reflection times,microcontroller 26 may track and produce a time profile of the positionof transducer 24 (i.e., plunger head 22). Based on the time profile ofthe position, microcontroller 26 may be able to identify a firstdistance D₁ or starting position (e.g., before medication 20 isdispensed), which may correspond with barrel 12 being filed and a seconddistance D₂ or ending position (e.g., after medication 20 is dispensed),which may correspond with barrel 12 being empty. Microcontroller 26 maythen calculate the change in distance between D₁ and D₂ and based off ofthe change in distance may calculate the volume (i.e., amount orquantity) of medication 20 dispensed.

In some embodiments, microcontroller 26 may be programmed toautomatically differentiate a portion of the volume dispensed as part ofan air shot versus the portion of volume injected into a patient. An airshot may be defined as priming of the medication injection device bydispensing a small quantity (e.g., 2 units) of medication 20 into theair prior to injection. An air shot is a common practice associated withmedication injection devices and the primary purposes are to removebubbles from the medication, fill the needle, and clear any potentialdebris from the needle (e.g., when a needle is reused). Failure todifferentiate the volume disposed as part of an air shot could lead tomore medication than was actually injected being recorded and this canlead to inaccurate medication injection records. By recognizing and airshot, microcontroller 26 can subtract the volume of medication dispensedduring the air shot from the total volume of medication 20 dispensed todetermine the actual volume of medication 20 injected in a patient. Insome embodiments, the volume of the air shot and the volume of theactual injection may be logged and recorded so a caregiver may monitorif recommended procedures (e.g., an air shot) are being followed.

Microcontroller 26 may be programmed to recognize an air shot using analgorithm based on one or more conditional states. The algorithm may beprogrammed to recognize a dispensed volume of medication as an air shotwhen there is a short gap (e.g., about 5 seconds, about 4 seconds, about3 seconds, about 2 seconds) between a first volume and a second volumeof medication being dispensed. In other words, a first volume ofmedication dispensed when there is a sequence of at least two or moredispensing events in a row may be recognized as an air shot. In someembodiments, the algorithm may also be programmed to incorporate andrecognize an air shot base on the volume of the amount disposed. Forexample, the algorithm may be programmed to recognize a dispensed volumethat is about equal to a recommend air shot volume (e.g., 2 units) as anair shot. In some embodiments, the algorithm may also be programmed toincorporate and recognize an air shot based on an orientation of themedical injection device or plunger head 22. For example, in someembodiments plunger head 22 may include an accelerometer thatmicrocontroller 26 may utilize to determine orientation. In someembodiments, the algorithm may also be programmed to incorporate andrecognize an air shot based on a rate of pressure decline of medication20 within barrel 12 after an initial movement of plunger head 22. Forexample, transducer 24 may function as a piezoelectric element andmeasure pressure of medication 20. Further it may be determined that afaster pressure decline may correspond with an air shot because for anair shot medication 20 is just being shot in the air against no backpressure. In comparison, when medication 20 is being injected into apatient there is a back pressure caused by the tissue.

In some embodiments, medication 20 may include an active medicationingredient and a buffer solution. The concentration of the activemedication ingredient may be known or programmed into microcontroller 26enabling the specific volume of the active medication ingredient to becalculated. In some embodiments, for example, the concentration of theactive medication ingredient may be stored in the non-volatile memory ofmicrocontroller 26. In some embodiments, additional informationregarding the medication 20 may also be stored, for example, ultrasonicvelocity vs. temperature data.

Transducer 24 and/or microcontroller 26 may be programmed to performvarious forms of signal conditioning in order to detect the time of thereflected ultrasonic signals 25. The signal conditioning may include,for example, amplification, filters, and envelope detection. Transducer24 and/or microcontroller 26 may use the signal conditioning todetermine for example, time to first rising edge or time to maximumreflective value in order to determine the reflection time.

Plunger head 22 may transmit data (e.g., the amount of medication 20dispensed and time and date it was dispensed) to a remote device (e.g.,a smart phone, a glucose monitor, an insulin pump, or a computer) viaone or more of the wireless communication methods. Plunger head 22 mayhave a unique identifier so the remote device may be able to identifyand process the information received properly. Plunger head 22 maytransmit this information to the remote device immediately or shortlyafter the medication is administered or plunger head 22 may store theinformation until the remote device is paired and within range. Theinformation may be stored, for example, in memory of microcontroller 26.In some embodiments, plunger head 22 may wait to initiate transmittingof the information to the remote device until initiated by the remotedevice. For example, a user may initiate information retrieval on theremote device. In some embodiments, the remote device may transmit theinformation to a caregiver (e.g., a doctor) or upload the information tothe cloud so it may be saved to the patient's medical history and may beaccessed by the caregiver. The ability of a caregiver or a patient toaccess and review the dose history may improve treatment. For example,the ability of a caregiver to review a diabetic insulin injectionhistory and continuous glucose measurement data may enable the caregiverto adjust the prescribed treatment to improve the therapeutic effect,for example, by better stabilizing the patient's glucose levels.

In some embodiments, plunger head 22 may also include a crystaloscillator 32 configured to keep a real time clock (RTC) so that thedate and time of each injection may be accurately recorded and stored inmemory of microcontroller 26. Crystal oscillator may be, for example, a32 KHZ crystal oscillator. In some embodiments, microcontroller 26 mayinclude an internal oscillator (e.g., RC oscillator), which may becalibrated using crystal oscillator 32. The internal RC oscillator maybe, for example, a 10 MHZ RC oscillator. Internal RC oscillator mayprovide sufficient time accuracy to measure the position (e.g., distanceD) of plunger head 22 to within, for example, about 150 microns. In someembodiments, transducer 24 may be used as an oscillator or as acalibrator for the internal RC oscillator. In some embodiments, thefrequency of the RC oscillator may be up-converted on microcontroller 26to a higher frequency. For example, the RC oscillator may be used todrive a higher-frequency phase-locked loop.

In some embodiments, plunger head 22 may be designed to back-interpolate the time of each injection enabling crystal oscillator 32 tobe eliminated. In order to maintain the RTC, crystal oscillator 32 mayconsume a significant amount of power, thus eliminating the crystaloscillator 32 can save a significant amount of power as well as savespace.

Plunger head 22 may back-interpolate the time of each injection byrelying on the real time clock of the remote device. The method ofback-interpolating may start with plunger head 22 taking and logging aseries of data samples (e.g., plunger head 22 positions). Plunger head22 may be programmed to take and log the data samples at anapproximately regular interval. The data samples, may be stored, forexample in a memory of microcontroller 26 in the order measured. Thedata samples may be logged and stored into memory with other data values(e.g., calculated injection volume, temperature, etc.). The collectionof logged data samples may be transferred/transmitted (e.g., uploaded)to a remote device, which will receive the data samples in the sameorder. The remote device may rely on the approximately regular intervalof the data sample logging to back-interpolate from the actual time attime of transfer, as determined by the RTC of the remote device. Byback-interpolating the approximate time of each data sample logged maybe determined. For example, if there were six samples transferred to theremote device and they were known to have been captured at about 60minute intervals then the remote device may determine the time of eachof the six samples were logged working backwards from the time of datatransfer. However, this example produces about a 60 minute uncertaintyin the calculated time of the data sample points because the time oftransfer may not be synchronized with the time of data sample logging.However, plunger head 22 may be programmed to log data samples at afaster frequency to reduce the uncertainty or increase the accuracy. Forexample, data samples may be logged every 30 minutes, 15 minutes, 10minutes, 5 minutes, 1 minute, or less than 1 minute.

The approximately regular interval may be determined or maintained by aless accurate, less power consuming, smaller timing device (e.g., anoscillator). It is noted that the reduce accuracy of the timing devicemay result in the approximately regular interval drifting due to avariety of factors, for example, temperature, voltage, or factorydetermined offsets. However, in some embodiments, plunger head 22 maystore the factory determined offsets and be programmed with instructionsto measure and log the temperature and/or voltage. Microcontroller 26may be programmed with instructions to use the factory determinedoffsets and the logged temperatures and voltages to generate a model tocorrect drift (i.e., change in interval) between the approximatelyregular intervals caused by variability in the temperature and thevoltage. This same method may also be used in other embodiments tocorrect drift even in a more accurate time tracking system (e.g., aquartz referenced system).

Although the above described back-interpolation and drift correctionmethod is described in reference to plunger head 22, it is contemplatedthat this method could be used in other sensor or sampling systems toprovide timestamps of useful accuracy for a sequence of sensor samplesthat do not contain an accurate time reference. This method providescost, power, and space savings while providing an accurate timereference for a sensor system.

Antenna or transceiver 30 may be used to communicate with a variety ofremote devices (e.g., smart phones, glucose monitors, insulin pumps,computers, etc.). Plunger head 22 may transmit the information via anysuitable wireless communication method. For example, in someembodiments, plunger head 22 may utilize radio data transmission,BLUETOOTH or (BLE), near field communication (NFC), infrared datatransmission or other suitable method. In some embodiments, informationmay also be wirelessly transmitted from a remote device to plunger head22 via antenna 30. For example, the date and time may be set by writingto microcontroller 26 via the wireless communication.

In some embodiments, plunger head 22 may also include a force sensor 34.Force sensor 34 may be configured to detect when a force is applied toplunger head 22 via plunger 14. Force sensor 34 may be, for example, asimple spring-loaded switch that is molded into the plunger head 22. Insome embodiments, transducer 24 may be configured to function as a forcesensor thereby eliminating the need for a separate force sensor 34. Forexample, transducer 24 may have a piezoelectric element that may detectthe dynamic changes in pressure when a user depresses plunger 14.

Power source 28 may be any suitable power source. For example, powersource 28 may be a battery, a capacitor, or the like. In someembodiments, power source 28 may be rechargeable via wireless energytransmission, for example, inductive coupling, resonant inductivecoupling, radio frequency (RF) link, or the like. In some embodiments,power source 28 may be a non-rechargeable battery that is configured tolast the storage and operational life of plunger head 22, for which thecombined storage and operational life may be about 1 year, about 2years, about 3 years, or more. For example, in some embodiments, powersource 28 may be a watch battery. In some embodiments, where plungerhead 22 is a passive device as described herein, power source 28 may beeliminated.

It is common for goods, including medical injection devices, to have along storage life between the time of manufacture and time of use/sale.Products that include embedded electronics, in particular a battery, itcan be a challenge to conserve battery power while the products are instorage. Some products have no on/off switch, buttons, orremovable/rechargeable batteries, so the traditional approach ofdisconnecting or turning off the device while in storage may not befeasible. Also, certain products (e.g., medical injection devices) thatinclude perishable goods (e.g., medication) it may be advantageous tohave the product monitor the storage environment (e.g., temperature,light, etc.) and log or store this data and this can't be done if thebattery is disconnected.

To address this challenge, plunger head 22 may be designed to enter alow-power sleep mode while in storage. Plunger head 22 may be programmedto enter low-power sleep mode as part of the manufacturing and testingprocess for plunger head 22 or the medication injection device. When inlow-power sleep mode the rate of power consumption may be a fraction ofthe rate of power consumption for normal operation. While in low-powersleep mode, microcontroller 26 may be programmed with instructions toperiodically wake up to measure the temperature. Microcontroller 26 mayalso log the temperature to create a temperature history. Alternatively,in some embodiments microcontroller 26 may be programmed to log thetemperature only when there is a change in temperature, thus saving ondata storage. The efficacy of some medications is affected bytemperature. For example, insulin is sensitive to hot and coldtemperatures. Plunger head 22 thus may monitor the temperaturemedication 20 through storage and up through use to ensure it stayswithin an acceptable range. If the temperature of the medication 20 goesoutside the acceptable range then plunger head 22 may be configured tosend an alert. The type of alert may vary. In some embodiments, plungerhead 22 may include a display (not shown in FIG. 2) and the alert may bea flashing light or a visual indicator. In some embodiments, plungerhead 22 may include a speaker and the alert may be auditory, forexample, a beeping sound. In some embodiments, the alert may betransmitted to a remote device and the remote device may display avisual alert and/or play an auditory alert.

In some embodiments, plunger head 22 may also be designed to utilize thetemperature measurement to transition between modes. For example, amedication injection device that includes plunger head 22 and medication20 may often be stored at a lower temperature (e.g., below a normal roomtemperature of about 20 to about 22 degrees Celsius). Subsequently,prior to use, often the temperature will be the medication device,including plunger head 22 and in particular medication 20 will be raisedto room temperature because injection of cold fluids can be painful.Thus, usually there will be a transition from a lower temperature to ahigher temperature shortly before use thereby triggering a change in themode of plunger head 22.

As described above, in lower power sleep mode plunger head 22 canperiodically measure the temperature, thus microcontroller 26 may beprogrammed to detect the temperature change that is expect prior to useand when detected microcontroller 26 may be programmed to transitionplunger head 22 from low-power sleep mode into an initialization mode.Microcontroller 26 may be programmed to pair with a remote device whilein the initialization mode. After a successful pairing, microcontroller26 may be programmed to transition plunger head 22 to an operationalmode and start sending and receiving ultrasonic waves and measuring theposition of transducer 24. In some embodiments, microcontroller 26 maybe programmed to reenter the low-power sleep mode if it is unable pairwith a remote device within a certain period of time (e.g., if no remotedevice is present). Microcontroller 26 may also be programmed to reenterthe low-power sleep mode after a period of inactivity (e.g., nomeasurable change in transducer 24 position after a programmed period oftime). Microcontroller 26 may also be programmed to reenter thelow-power sleep mode if a subsequent temperature change (e.g., adecrease in temperature from normal room temperature) is detected.Microcontroller 26 may be programmed to transition directly from thelow-power sleep mode back to the operational mode if a successfulpairing with a remote device has already occurred.

In some embodiments, plunger head 22 may also be configured to detectair bubbles in medication 20. Air bubbles if injected can be deadly sodetection of air bubbles is advantageous. In order to detect airbubbles, transducer 24 of plunger head 22 may be configured to detectsmall ultrasonic echoes created by the reflection of the ultrasonicwaves off the air bubbles in addition to the main echo caused by the endof barrel 12. Plunger head 22 may be configured to transmit an alert ifair bubbles are detected. The alert may be communicated in the same waysas the temperature alert described above.

In some embodiments, plunger head 22 may also be configured todifferentiate, verify, and/or identify medication 20 contained insyringe 10. For example, when barrel 12 is loaded with medication 20,plunger 14 and plunger head 22 may be pulled all the way back to itsstopping point and the distance from plunger head 22 to end 27 of barrel12 may be known enabling microcontroller 26 to solve for the speed ofsound of the fluid, which depends on temperature and density. Thetemperature may be measured by temperature sensor 36 so the density maybe determined and based on the density the amount of solids dissolved inthe fluid may also be determined. In addition, the viscosity of themedication 20 may be measured based on the amplitude of the reflectedultrasonic signals 25 because more viscous fluids dissipate more energy.In some embodiments, plunger head 22 may also include electrodes 38connected to microcontroller 26 configured to measure the conductivityof medication 20. In some embodiments, the electrodes 38 may protrudeout from the surface of plunger head 22 into barrel 12 where theelectrodes 38 may contact medication 20. With the density, conductivity,and viscosity of medication 20 determined, microcontroller 26 may have asufficient number of properties to profile medication 20. In someembodiments, the profiling may be configured to differentiate medication20 in order to determine if it from a prescribed class of medication. Insome embodiments, the profiling may be configured to verify thatmedication 20 is the same as the medication that is prescribed for thepatient. In some embodiments, the profiling may be configured toidentify the medication 20.

According to an exemplary embodiment, plunger head 22 as describedherein may be combined with a syringe that has been modified to includea piezo linear motor. The piezo linear motor may be incorporated intothe wall of the barrel of the syringe and a piezo element may beincorporated into plunger head 22. The piezo linear motor may beconfigured to drive or “walk” the plunger head 22 down the barrel of thesyringe by driving the piezo element, thereby forcing the medicationfrom the syringe. This embodiment may enable the piezo linear motor tocontrol medication dispensing while plunger head 22 may simultaneouslytrack the amount of medication being dispensed. In some embodiments,plunger head 22 may control the piezo linear motor or plunger head 22can communication with a remote device that can control the piezo linearmotor such that it dispenses a set amount of medication.

FIG. 6 shows a smart syringe system 40, according to an exemplaryembodiment. System 40 may be designed for use with a standard disposablesyringe 10 or other medication injection devices. Similar to plungerhead 22, smart syringe system 40 may be configured to measure andregister the quantity of medication 20 administered and the date andtime of administration. Smart syringe system 40 may include a smart orintelligent plunger head 42, similar to plunger head 22, and a cuff 44.In some embodiments, plunger head 42 may be designed to be disposableafter a single use while cuff 44 is reusable. Embodiments of plungerhead 42 designed to be disposable after a single use may houses only theminimum number of components to carry out its function while anyoptional or ancillary components may be housed in cuff 44 to minimizemanufacturing cost of plunger head 42. The manufacturing cost of plungerhead 42 may also be minimized by using lower cost components (e.g.,transducers, antennas, and microcontrollers) and materials (e.g.,rubbers, polymers, plastics) that are less robust and durable, andinstead may be designed for shorter operational life spans.

Plunger head 42 may be designed to be supplied with or installed into adisposable syringe 10 and after administering a dose of medication 20,syringe 10 along with plunger head 42 may be disposed of or recycled. Incontrast, cuff 44 may be designed to be reused numerous times. Forexample, a disposable syringe 10 may be inserted through cuff 44 andafter medication 20 is administered; cuff 44 may be removed from theused syringe 10 and be saved for later use.

In some embodiments, both plunger head 42 and cuff 44 may be reusable.For example, after medication 20 is administered by syringe 10, bothplunger head 42 and cuff 44 may be removed and saved for later use.

Plunger head 42 and cuff 44 can come in different sizes so they may beused with any size syringe. For example, plunger head 42 may be sized tofit within the barrel 12 of any size syringe 10 while cuff 44 may beconfigured to have a passage 46 configured to receive any size barrel 12of syringe 10.

Plunger head 42 and cuff 44 (i.e., the smart syringe system 40) incombination may be configured to have some or all of the same components(e.g., a transducer 24, a microcontroller 26, a power source 28, anantenna 30, crystal oscillator 32, force sensor 34, and a temperaturesensor 36) as plunger head 22 and perform at least all the sameoperations as plunger head 22. Some of the components may be housed inplunger head 42 while some of the components may be housed in cuff 44.To reduce the manufacturing cost of plunger head 42, as described above,plunger head 42 may be designed to house the minimum number ofcomponents to carry out its functions. For example, system 40 may beconfigured such that all the components that can be housed in cuff 44are, rather than plunger head 42. In some embodiments, such componentsmay include a form of memory for data storage.

According to an exemplary embodiment, plunger head 42 may include thetransducer 24, antenna 30, and a microcontroller 26 while cuff 44 mayalso include a separate microcontroller, a power source, and a separateantenna. To reduce complexity, plunger head 42 may be passive (e.g.,battery-free) and configured to be controlled and powered by cuff 44 viawireless energy transmission. Cuff 44 may also be configured tocommunicate with a remote device (e.g., a smart phone, a glucose sensor,an insulin pump, or a computer) thereby enabling the volume ofmedication and the time and date of administering to be uploaded toanother device or the cloud.

In some embodiments, cuff 44 may include a display. Cuff 44 may beconfigured to display any alerts (e.g., high temperature or impropermedication) to the user. Cuff 44 may also display the volume, date, andtime after medication has been dispensed. The display may also beconfigured to allow user input (e.g., touch screen). For example, theuser may program in the date, the time, the type of medication or otherinformation.

Plunger head 22 and system 40 described herein may be utilized for avariety of methods for tracking administering of a medication to apatient delivered by syringe. Various methods of utilizing plunger head22 and system 40 will now be explained with reference to FIG. 7. In someembodiments, the methods as described herein may be performed by acaregiver (e.g., a doctor or nurse) in a hospital or other inpatientsetting. In some embodiments, the methods as described herein may beperformed by a caregiver (e.g., a doctor, nurse, or parent) at home oroutside a hospital. In some embodiments, the methods as described hereinmay be performed by the patient. It is contemplated that the methodsdescribed herein may be performed in other settings by otherindividuals.

Plunger head 22 may be utilized for a method 100 of trackingadministering of a medication to a patient delivered by a medicationinjection device (e.g., a syringe), according to an exemplaryembodiment. In some embodiments, at step 102, method 100 may begin byinstalling plunger head 22 into barrel 12 of syringe 10 (e.g., adisposable syringe). In some embodiments, syringe 10 may be suppliedwith plunger head 22 already installed. For embodiments corresponding toother medication injection devices (e.g., insulin pen), plunger head 22may be installed as part of the original manufacturing process, whichmay also include loading of medication 20 (e.g., insulin)

Optionally, at step 104, the barrel 12 of the syringe may be filled withthe medication 20. This step may be eliminated for embodiments were themedication 20 comes prefilled. The barrel 12 may be completely filled oronly partially with medication 20.

At step 106, the syringe may then be positioned for administration. Forexample, the needle may be inserted into the skin of the patient or intoa drug delivery port connected to the patient. Once in position, theplunger 14 of the syringe 10 may be depressed, which forces plunger head22 down the barrel 12 and forces the medication 20 out the needle 16.Optionally, prior to step 106, method 100 may also include performing anair shot which may be automatically differentiated from the actualinjection.

In some embodiments, the initial position of plunger head 22 (e.g., thedistance between plunger head 22 and end 27) may be known by plungerhead 22. For example, syringe 10 may be full and plunger head 22 mayknow the distance between plunger head 22 and end 27 when filled. Insome embodiments, if syringe 10 is used multiple times to deliver amedication 20, the previous position of plunger head 22 may be knownfrom the last measurement stored. In some embodiments, the initialposition of plunger head 22 may be measured using plunger head 22 priorto any medication 20 being delivered, as described below.

Prior to and while plunger 14 is being depressed, plunger head 22 maysend and receive ultrasonic signals 25 via transducer 24, at step 108.Plunger head 22 may send and receive ultrasonic signals 25 the durationof the time the plunger is being depressed. Plunger head 22 may measurea time it takes for each of the ultrasonic signals to travel through themedication to an end of the barrel and return to the transducer, at step110. In some embodiments, at least a portion of the ultrasonic signals25 may be sent and received before any medication 20 is dispensedenabling the initial position of plunger head 22 and initial volume ofmedication 20 to be calculated.

As described herein, at step 112, plunger head 22 may calculate theposition of plunger head 22 and a distance plunger head 22 travels overthe course of dispensing medication 20. At step 114, the quantity ofmedication 20 dispensed may be calculated based on the calculateddistance the plunger head 22 traveled. As described herein, in someembodiments plunger head 22 may automatically differentiate an air shotand if an air shot is performed may subtract the volume of medication 20dispensed as part of the air shot from the total volume dispensed inorder to determine the actual volume of medication 20 injected.

For some embodiments of method 100, the calculation of the quantity ofmedication dispensed may be performed by a remote device (e.g., a smartphone, a glucose sensor, an insulin pump, or a computer). In someembodiments, method 100 may also include transmitting the quantity ofthe medication dispensed and the time and date the quantity wasdispensed to a remote device. In some embodiments, method 100 may alsoinclude uploading the quantity of the medication dispensed and the timeand date the quantity was dispensed to the cloud. In some embodiments,method 100 may also include sending the quantity of the medicationdispensed and the time and date the quantity was dispensed to acaregiver.

For some embodiments, method 100 may also include logging a plurality ofdata samples (e.g., position of plunger head 22) at an approximatelyregular interval and then back-interpolating the time corresponding toeach data sample logged to determine the approximate time the quantityof medication 20 was disposed using the RTC maintained by the remotedevice as a reference time.

Although method 100 is described with reference to plunger head 22, itmay also be performed by system 40, as described herein.

The foregoing description has been presented for purposes ofillustration. It is not exhaustive and is not limited to precise formsor embodiments disclosed. Modifications and adaptations of theembodiments will be apparent from consideration of the specification andpractice of the disclosed embodiments. For example, the describedembodiments of plunger head 22, 42 and cuff 44 may be adapted for usedwith a variety of other medication injection devices, including forexample, auto-injectors, auto-syringes, injector pens (e.g., insulinpens), or other drug or medication injection devices.

Moreover, while illustrative embodiments have been described herein, thescope includes any and all embodiments having equivalent elements,modifications, omissions, combinations (e.g., of aspects across variousembodiments), adaptations and/or alterations based on the presentdisclosure. The elements in the claims are to be interpreted broadlybased on the language employed in the claims and not limited to examplesdescribed in the present specification or during the prosecution of theapplication, which examples are to be construed as nonexclusive.Further, the steps of the disclosed methods can be modified in anymanner, including reordering steps and/or inserting or deleting steps.

The features and advantages of the disclosure are apparent from thedetailed specification, and thus, it is intended that the appendedclaims cover all systems and methods falling within the true spirit andscope of the disclosure. As used herein, the indefinite articles “a” and“an” mean “one or more.” Similarly, the use of a plural term does notnecessarily denote a plurality unless it is unambiguous in the givencontext. Words such as “and” or “or” mean “and/or” unless specificallydirected otherwise. Further, since numerous modifications and variationswill readily occur from studying the present disclosure, it is notdesired to limit the disclosure to the exact construction and operationillustrated and described, and accordingly, all suitable modificationsand equivalents may be resorted to, falling within the scope of thedisclosure.

Computer programs, program modules, and code based on the writtendescription of this specification, such as those used by themicrocontrollers, are readily within the purview of a softwaredeveloper. The computer programs, program modules, or code can becreated using a variety of programming techniques. For example, they canbe designed in or by means of Java, C, C++, assembly language, or anysuch programming languages. One or more of such programs, modules, orcode can be integrated into a device system or existing communicationssoftware. The programs, modules, or code can also be implemented orreplicated as firmware or circuit logic.

Other embodiments will be apparent from consideration of thespecification and practice of the embodiments disclosed herein. It isintended that the specification and examples be considered as exampleonly, with a true scope and spirit of the disclosed embodiments beingindicated by the following claims.

1. A method of tracking injections of a medication delivered by amedication injection device, the method comprises: depressing a plungerof the medication injection device; sending and receiving ultrasonicsignals from a plunger head installed within a barrel of the medicalinjection device; measuring a time of flight for the signals to travelthrough the medication to an end of the barrel and return to the plungerhead; determining a position of the plunger head based on the time offlight of the signals and logging a data sample representative of theposition; logging a plurality of the data samples representative of theposition of the plunger at an approximately regular interval;calculating a distance the plunger head travels based on a change in theposition; calculating a quantity of the medication dispensed based onthe distance the plunger head travels; transmitting wirelessly thequantity of the medication dispensed to a remote device;back-interpolating a time corresponding to each data sample logged inorder to determine the time the quantity of medication was dispensed,using a timekeeper in the remote device as a reference.
 2. The method ofclaim 1, wherein an oscillator is used to determine the approximatelyregular interval.
 3. The method of claim 2, further comprising measuringand logging a temperature and a voltage associated with the oscillator.4. The method of claim 3, further comprising using the loggedtemperature and the logged voltage to correct for drift of theapproximately regular intervals caused by variability in the temperatureand the voltage.
 5. The method of claim 4, further comprising usingfactory determined offsets for the oscillator in addition to the loggedtemperature and voltage to correct for the drift.
 6. The method of claim1, wherein the approximately regular interval is 60 minutes or less. 7.The method of claim 1, wherein the remote device includes at least oneof a smart phone, a glucose monitor, an insulin pump, or a computer. 8.The method of claim 1, wherein transmitting wirelessly includes at leastone of radio data transmission, BLUETOOTH or (BLE), near fieldcommunication (NFC), infrared data transmission.
 9. A plunger head for amedication injection device, comprising: a transducer that sends andreceives ultrasonic signals; an antenna; a temperature sensor coupled tomeasure a temperature; a controller coupled to the transducer, theantenna, and the temperature sensor, wherein the controller includeslogic that when executed by the controller causes the controller toperform operations including: placing the plunger head in a low-powersleep mode; and placing the plunger head in a high-power mode, relativeto the low power sleep mode, to measure the temperature.
 10. The plungerhead of claim 9, wherein the controller further includes logic that whenexecuted by the controller causes the controller to perform operationsincluding: transitioning the plunger head into an initialization modeafter detecting a temperature change, wherein the temperature changecorresponds to an increase in temperature from a storage temperature toa room temperature.
 11. The plunger head of claim 10, wherein thecontroller further includes logic that when executed by the controllercauses the controller to perform operations including: pairing theplunger head with a remote device while in initialization mode.
 12. Theplunger head of claim 11, wherein the controller further includes logicthat when executed by the controller causes the controller to performoperations including: transitioning the plunger head into an operationalmode after successfully pairing with the remote device.
 13. A method ofoperation for a medication injection device that has a temperaturesensor that measures an ambient temperature, the method comprising:placing the medication injection device into a low-power sleep mode;measuring the ambient temperature while in the low-power sleep mode at aregular interval; detecting a temperature change with the temperaturesensor, transitioning the medication injection device into aninitialization mode, in response to the temperature change; pairing themedication injection device with a remote device while in theinitialization mode; entering an operational mode after a successfulpairing of the medication device with the remote device; and measuringand logging a plunger head position of the medication injection deviceonce the medication injection device is in the operational mode.
 14. Themethod of claim 13, wherein the medication injection device enters thelow-power sleep mode as part of a manufacturing and testing process forthe medication injection device.
 15. The method of claim 13, furthercomprising returning to the low-power sleep mode after a period ofinactivity.
 16. The method of claim 13, wherein the temperature changethat triggers the transition into the initialization mode is an increasein temperature from a storage temperature to a room temperature.
 17. Themethod of claim 13, further comprising returning to the low-power sleepmode when a subsequent temperature change is detected, wherein thesubsequent temperature change is a decrease in temperature.
 18. Themethod of claim 13, further comprising transitioning the medicalinjection device from the low-power sleep mode directly back to theoperational mode after the pairing of the medication injection devicewith a remote device.